Hello Mike and thank you for your question.
Installing a whole house (automatic back-up) generator requires the skills of a plumber and an electrician. Local or municipal codes, utility companies (electric and gas - natural or propane), home owner association agreements, and restrictive covenants may also influence which, when, and by whom a generator can be installed. These factors will affect the cost of the installation. We recommend that you consider professional installation due to the complex nature of a stand-by generator.
The Home Depot has a Generator Installation program available through our Home Services division (http://www.homedepot.com/webapp/cat...
) that can provide a free in-home estimate and advise you of local codes which will influence your install.
Best wishes on your project.